The Effect of Repetitive Transcranial Magnetic Stimulation on Suicidal Ideation in Treatment-Resistant Depression: A Meta-Analysis

Objective: To quantitatively synthesize the literature on the effects of repetitive transcranial magnetic stimulation (rTMS) on suicidal ideation (SI) in patients with treatment-resistant depression. Data Sources: A literature search was conducted using PubMed, SCOPUS, Ovid, MEDLINE, Embase, and Web of Science from inception to January 11, 2021, for the keywords repetitive transcranial magnetic stimulation, suicidal ideation, suicidality, treatment-resistant depression, refractory depression, transcranial magnetic stimulation, and brain stimulation. Study Selection: A total of 16 publications were eligible for inclusion. Studies were included that investigated the effects of rTMS in adolescents and/or adults 16 years or older diagnosed with unipolar or bipolar depression with suicidal ideation data before and after rTMS intervention. Data Extraction: Data were extracted and managed using Covidence. Extracted data included authors, publication year, country of origin, study design, patient demographics, primary diagnosis, comorbidities, mean age, outcome assessment instruments, detailed stimulation parameters, sham control procedures, and any serious adverse events related to SI. Results: A quantitative analysis of effect size using Hedges g was calculated for both randomized controlled trials and all other uncontrolled trials. We found a decrease in SI scores in randomized controlled trials (g = 0.158, 95% confidence interval [CI] = -0.078 to 0.393, P =.191), although the effect was not significant. There was a significant decrease in suicidal ideation scores for uncontrolled trials (g = 0.692, 95% CI = 0.463 to 0.922, P <.001). Conclusions: Our findings suggest that rTMS may be an effective treatment for SI in individuals with treatment-resistant depression, although further investigation is warranted.